The province of Skikda, located in the northeast of Algeria, has undergone rapid industrialization, marked by the establishment of large factories discharging their liquid waste into local waterways. These industrial discharges have led to water pollution, seriously threatening the long-term environmental balance. This book focuses on the state of aquatic environments in this region, highlighting the physicochemical and biological qualities of an endangered watercourse.The analysis of physicochemical parameters, such as turbidity, conductivity, and the presence of chemical substances, will reveal the extent of pollution and its effects on water quality. Furthermore, the study of aquatic biodiversity, particularly macroinvertebrates, will enable the assessment of pollution impact on local ecosystems.This book aims to raise awareness of environmental issues in the Skikda region and to encourage measures for the preservation and restoration of aquatic environments. By providing a detailed overview of the situation, it offers insights for sustainable management of natural resources, essential for ensuring a healthy future for the region and its inhabitants.